There are numerous circuits and other electronic devices that produce energy waves such as electromagnetic waves and microwaves. These circuits produce energy waves that are delivered to a destination through different wires, guides, and other mediums.
Energy waves can be difficult to control on various circuits, cables, wires, and other mediums that transport the energy waves because these mediums are “lossy.” Lossy materials and mediums loose energy by radiation, attenuation, or dissipation as heat. By being lossy, a portion of the signal is lost as is travels through the circuits, wires, and other mediums. Stated another way, a signal entering a lossy material will be greater at the point of entry than at the point of exit.
Microwave energy is particularly difficult to control as many of the materials and mediums that transport microwave energy are lossy. One exemplary circuit that generates and transports microwaves is a “monolithic microwave integrated circuit” or “MMIC.” Lost signal waves are unusable and decrease the efficiency of a MMIC as the signal strength decreases due to loss. Generally, the higher the frequency of the microwave, the more lossy the transmission medium and more inefficient the circuit. In certain applications, even signal losses that reduce the signal small amounts, such as 1/10 of a decibel, may result in a significant performance loss. One exemplary application where loss from energy waves such as microwaves is problematic is a power amplifier.
One structure used to reduce lossiness is a waveguide. Waveguides are structures that guide energy waves with minimal signal loss. Unfortunately, signal loss is still problematic with certain waves because the connection or interface between the circuit generating the energy waves and the waveguide can be lossy itself. This is especially an obstacle with a MMIC generating microwaves. Moreover, impedance mismatches also cause signal losses. For example, the impedance of the MMIC, for example fifty ohms, may not match the impedance of the connected waveguide, for example two hundred and seventy ohms. In this example, an interface between the waveguide and MMIC attempts to match the fifty ohm impedance of the MMIC with the two hundred and seventy ohm impedance of the waveguide. These types of interfaces are known generally as “impedance matching interfaces” or “impedance matching and transforming interfaces.” Throughout, the term “interface” is meant to denote an “impedance matching interface” or “impedance matching and transforming interface.”
Current interfaces between a MMIC and waveguide comprise numerous structures that include wirebonds, microstrips, pins, and other devices to connect a circuit to a waveguide or another structure. These interfaces also attempt to match and transform the impedance of the MMIC to the impedance at the waveguide. However, current impendence matching interfaces between an integrated circuit such as a MMIC and a waveguide still have an unacceptable amount of loss.
Therefore, it would be advantageous to provide an interface between an integrated circuit, such as a MMIC, and a waveguide, or other structure that reduces signal loss. It would also be advantageous to produce an interface that reduced loss that was inexpensive and easy to manufacture, particularly one that was constructed from parts that were commercially available.